The reports claim that the picture was discovered amongst items belonging to Bob Guccione, the founder of adult magazine Penthouse who passed away in 2010.

The possessions, held in a storage space, reportedly also include unpublished nude images of Madonna and actress Lauren Hutton.

Meanwhile, files explaining Guccione's decision to publish naked pictures of Vanessa Williams - which ended with her being forced to resign her Miss America 1984 crown amid a storm of controversy - are also thought to be included in the boxes.

Guccione's possessions have come to light after an unknown person allegedly bought up his lockers when he went bankrupt, although it is not yet clear whether the new owner plans to release any of the material.

Meanwhile, Schwarzenegger's spokesperson has not yet commented on the reports.